Different types of drinker are known in commerce, such as open system and close system. The open system, in which the water is directly in front of the poultry eyes, consist in a metallic container or plastic container when dealing with manual drinkers, having the mouth in an inverted position and on which there is a dish which delivers water in a dosing manner, when the poultry place their beak in the dish; with the disadvantage that the poultry soils the water with food, or frequently they return the drunk water into the dish thus contaminating the same. This type of drinker is referred to as bell type, channel type, can type etc.
There also are open type automatic drinkers in general bell type which receive the water directly from a water tank and deliver the water to poultry when ever needed. As it is an open system it is necessary to wash all at least once every day with the consequent problem of having personnel in and out constantly which besides molesting the poultry this can be a vehicle for poultry diseases.
The nipples correspond to the closed system and due to its design, the water in it cannot be soiled by the birds. The water that the poultry drink is that which the farmer gives them, which must be of excellent quality.